Driver zndrv1

and
The action ${\bf w}\leftarrow{\bf A}{\bf v}$ is required in this driver.

• ido=1
  Action Required:

  Matrix vector multiplication ${\bf w}\leftarrow{\bf A}{\bf v}$.
  The vector is in workd(ipntr(1)).
  The result vector must be returned in the array workd(ipntr(2)).